A wind turbine typically comprises several units which generate excess heat. Examples of such components are gearboxes, transformers, bearings, generators, and power converters etc.
Such units are typically housed in a closed space within the tower or nacelle and heat exchange with the ambient space is limited. Often, active cooling, e.g. by use of a flow of air or a cooling liquid between the units and a heat exchanger, is necessary.
One commonly applied cooling structure for electrical components includes a fan for generating air flow around the electrical component or for generating air flow through a heat exchanger coupled to the component.
Particularly, very large wind turbines may include heat exchangers attached outside the nacelle, e.g. fixed to the roof of the nacelle. Since the nacelle is typically actively turned such that the rotor plane is always orientated into the wind, such roof-mounted heat exchangers also become orientated into the wind. The heat exchangers are therefore arranged side-by-side facing in one common direction, namely forward with respect to the nacelle and rotor plane.
U.S. Pat. No. 7,168,251 discloses a liquid cooled wind turbine with heat exchangers arranged outside the tower.
Since heat exchangers alongside of the tower, in contrast to the roof-mounted heat exchangers, are partly sheltered by the tower wall, such radiators typically lacks efficiency, and electrically powered fans must typically be applied for creating a forced flow of ambient air through the heat exchangers. This increases operation costs and makes the wind turbine more vulnerable.